Salesforce CEO Marc Benioff left a strong message for his 25,000 employees last month after seeing alcoholic drinks and kegs sitting in the office: take them out.

“I want to remind everyone that we have a no alcohol policy at Salesforce,” Benioff wrote in an internal blog post, according to a person familiar with the matter. “Alcohol is a drug and having alcohol on a Salesforce premise is simply unfair to the Ohana who either do not want it or are intolerant of it.”

Benioff, who often calls his employees “Ohana,” the Hawaiian word for family, isn’t the only public company CEO to enforce a no drinking policy at work. But he’s certainly one of the first tech CEOs to put a hard ban on workplace drinking — a trendy office perk in Silicon Valley that has almost become the norm among tech companies as they try to attract talent with a more laid back office culture.

Office booze has gained popularity, particularly among tech startups run by young CEOs, as it helps avoid an old, stodgy company image and is believed to encourage an environment where employees enjoy their time together.

Companies like Twitter and Glassdoor have multiple kegs of beer available free of charge to employees at any time. Yelp and GitHub have free booze but only allow access after work or in certain parts of the office. Facebook and Google don’t have an official ban on alcohol, but employees are expected to use common sense when it comes to drinking.

But a growing number of tech companies are starting to kick alcohol out of the office entirely.

Start-up Zenefits banned office drinking last year as part of its effort to clean up its party-like work culture. Uber is considering a similar ban during “core working hours,” and reduce the budget for drinks during after-hour events, based on recommendations by an outside law firm. Jet.com has gotten stricter about enforcing a no-booze rule after getting acquired by Walmart, which doesn’t allow office drinking, according to The Wall Street Journal.

Salesforce officially announced an alcohol ban at an all-hands meeting held more than a year ago, another person said. It’s unclear what inspired the change, but Benioff has shared his thoughts about it on Twitter last year, when he wrote, “No room for alcohol or drugs in a start up or tech culture. The CEO has to set the tone from the top and enforce.”

Salesforce did not comment for this story.

There are plenty of reasons for companies to think twice about offering free booze or allowing office drinking. It’s not only an added cost to the company’s expense, but it also increases the likelihood of bad behavior, like sexual harassment, which has become a growing problem in the tech industry. And, as Benioff points out, it could make non-drinkers feel left out.

But the biggest risk lies in the potential liability issues that follow, according to Peter Cappalli, a management professor at the Wharton School. If an employee gets in trouble, like a car accident, after drinking alcohol provided by the employer, the company could be legally liable for the damage, he said.

“Employers are rightly concerned about legal liability for actions that their employees take either at work or after hours when they have been drinking alcohol provided by the employer,” Cappalli said. “If I’m injured by a drunk employee, I’m likely to sue their employer because the employer has more money.”

Still, not everyone’s happy with Salesforce’s decision to ban office drinking. Some Salesforce employees aired their frustration on Blind, an anonymous chat app that requires users to have a working company email in order to post about their employer.

In a message in a public forum seen by CNBC, one person wrote that office drinking should be a choice, and shouldn’t be considered an inclusivity issue because no one’s forcing others to drink.

“It’s not as if drinking was mandatory by any means,” the person wrote. “It seems like excluding something optional under the guise of inclusivity doesn’t make any sense logically.”